Abstract

A RHRP (Reduced-Height and Reduced-Pressure) IIST (Institute of Nuclear Energy Research Integral System Test) facility has been established in 1992 for safety studies of the Westinghouse three-loop PWR (Pressurized Water Reactor) NPP (Nuclear Power Plant). The research purposes of the IIST facility are as follows: (a) to enhance the understanding of thermal hydraulics phenomena during the accidents, (b) to contribute to evaluate and develop the safety computer codes, and (c) to validate the emergency operating procedure (EOP) during the accidents of PWR. The scaling factors of the IIST facility for height and volume of the reactor coolant system (RCS) are approximately 1/4 and 1/400, respectively. The maximum operating pressure of the IIST facility is 2.1 MPa. The IIST facility has three loops as well as all the systems which are about studying Westinghouse PWR plant system transients. The experiment of the IIST facility was finished which simulated a 2% cold-leg-break loss-of-coolant accident (LOCA) with total high-pressure injection (HPI) failure. This break was located in loop 2 of IIST facility, which is one of the two loops that do not have a pressurizer. Besides, three cooldown experiments of IIST facility were also performed. In this research, the IIST facility experiments data and RELAP5 analysis results of IIST facility experiments are used to verify and establish the TRACE (TRAC/RELAP Advanced Computational Engine) IIST facility models. Comparing steady state results, it can be concluded that the steady state results of TRACE calculations are in agreement with those of IIST facility experiments data and RELAP5 analysis results of IIST facility experiments. On the other hand, comparing the transient results, it also indicates that they are in reasonable consistency. The verified results of TRACE IIST facility models reveal that there is respectable accuracy in the analysis of the 2% cold-leg-break LOCA and cooldown experiments.